1. Technical Field of the Invention
The present invention relates to a detecting system for detecting a surface flaw of a cylindrical object such as a can or a roll or a curved object such as a sphere by means of measuring an uneven form and height displacement of the object surface using a light-section method.
2. Background of the Related Art
FIG. 32 shows a conventional example (refer to the Unexamined Japanese Patent Publication No. Hei 6-167455). Here, one point of an inspected object 1 having a cylindrical appearance rotated and translated is irradiated with a light beam through a lens 3 from a light source 2, scattered light is imaged and detected by a detector 5 through a lens 4 from a different direction from a light transmission axis X of the light, and detection output of the detector 5 is input through an amplifier 6 to an A/D converter 7, which then converts the detection output from analog form into digital form. At the time, sampling is executed for a predetermined sampling rate by a timer 8. The converted data is sent to a microprocessor 11 via a store 9, which then makes a comparison between normal and defective faces, thereby detecting a defect, then displays the result on a display 12 and sends a control signal to a scrapping controller 13 for scrapping the inspected object 1.
By the way, in the conventional system, while a spot-like light beam is emitted, the inspected object 1 is rotated. Thus, desirable inspected area cannot be imaged at the same time and a dead zone (undetectable area) occurs between the spot beams. The two-step operation of rotating and translating the inspected object is required and the mechanism is complicated.